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<H2><A NAME="SECTION03519000000000000000"></A><A NAME="subsecinfo"></A>
<BR>
Error Handling and the Diagnostic Argument INFO
</H2>

<P>
All<A NAME="19566"></A> documented routines<A NAME="19567"></A> have a 
diagnostic argument INFO<A NAME="19568"></A><A NAME="19569"></A> that
indicates the success or failure of the computation, as follows:

<P>

<UL><LI>INFO = 0: successful termination

<P>

<LI>INFO <B>&lt;</B> 0: illegal value of one or more arguments -- no computation
performed

<P>

<LI>INFO <B>&gt;</B> 0: failure in the course of computation

</UL>

<P>
All driver and auxiliary routines
check that input arguments such as N or LDA or
option arguments of type character
have permitted values.
If an illegal value of the <B><I>i</I><SUP><I>th</I></SUP></B> argument is detected, the routine
sets INFO = <B>-<I>i</I></B>, and then calls an error-handling routine XERBLA.
<A NAME="19573"></A><A NAME="19574"></A>

<P>
The standard version of XERBLA issues an error message and halts execution,
<A NAME="19575"></A>
so that no LAPACK routine would ever return to the calling program with
INFO <B>&lt;</B> 0. However, this might occur if a non-standard version of XERBLA
is used.

<P>
<BR><HR>
<ADDRESS>
<I>Susan Blackford</I>
<BR><I>1999-10-01</I>
</ADDRESS>
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